that does suck! I hope they replace it, it should last longer than 3 hrs!
DBA, I have a pit, he does the same thing with my QH mare. He'll chase her for awhile, she'll chase him for awhile. If he's not in the pasture, he runs up and down the fence, she will stand there and act like she wants to kill him thru the fence. It gets funny. She did kick him once, knocked him smooth out! I thought he was a gonner, he stood up, leaned significantly to one side, and wobbled. He finally stood up straight, ran straight to the gate with a "let me out of here" attitude, when we opened the gate, he ran straight to the truck and got inside and laid down! It didn't stop him. Next time we were at the horses with him. He went right at her again. But, they play now, he never was aggressive, just chases her. He doesn't do it as much, but they still will go out there and play, chasing each other